A lot of the time we find if you take the dog for a walk and then introduce yourselves you usually get a few invites. Or just invite yourself to “5 Oclock” as most people don’t mind if you park yer bum for a yarn and a brew.
Or just wander around with a drink in your hand looking lost, that works for me
Generally you will be welcome, it would be a low sort to not let you join in.
Dave